1. Field of the Invention
This invention generally relates to integrated optical devices and, more particularly, to acousto-optical systems wherein surface acoustic waves interact with light.
2. Description of the Prior Art
In the field of integrated optics, optical systems and devices are constructed on planar surfaces. These systems are designed to have a more compact form and smaller size than comparable bulk optical devices. In addition, integrated optical devices are developed to be compatable with other planar technologies such as integrated electrical circuits and surface acoustic wave propagating media.
In this area of technology it is well known to propagate light through a material near its surface by using an optical wave guide. Such a wave guide is formed by locating a region in the material that has a higher refractive index than the surrounding material. It is also well known in optics that imperfections and perturbations can be used to scatter light out of a wave guide in predominantly one direction.
The concept of colinear acousto-optic interaction was initially proposed by Mr. W. S. C. Chang in an article in the IEEE Journal of Quantum Electronics entitled "Acousto-optical Deflections in Thin Films," April 1971, pages 167-170. Thereafter, this interaction was theoretically described by Mr. T. G. Giallorenzi in an article entitled "Acousto-optical Deflection in Thin-film Waveguides," Journal of Applied Physics, Vol. 44, No. 1, January 1973, pages 242-253. An experimental demonstration of this effect was described by Messers. F. R. Gfeller and C. W. Pitt in an article entitled "Co-linear Acousto-optic Deflection in Thin-films", Electronics Letters, Nov. 2, 1972, Vol. 8, No. 22, pages 549-551.